The Prostate Cancer Prevention Trial [6] reported that 39.2% of men with a PSA 2.1–3.0 ng/mL, 27.7% of men with a PSA 1.1–2.0 ng/mL, and 1.3% of men with a PSA <1.0 ng/mL had end of trial prostate biopsies with foci of adenocarcinoma. Here, KLK3 is linked to prostate carcinoma.